mixin open-close() 
  h1 open
  -var w = 900
  -var h= 900
  section(style="height:0; pointer-events: none; transform: rotateZ(0)")
    svg(viewBox="0 0 ${w} ${h}" width="100%", opacity="0", style="display:block")
      set(attributeName="visibility" to='hidden' begin='touchstart' dur="0.21s", restart="always")
